From 042c47b5c17979ebd3971b9d9d4fd50680e8a65d Mon Sep 17 00:00:00 2001
From: Martin Melka <melkamar@users.noreply.github.com>
Date: Mon, 25 Aug 2025 17:58:08 +0200
Subject: [PATCH] Add compatibility note to 'c' date format

The 'c' format produces invalid ISO8601 dates for years 10000
and above. This is not necessarily wrong, but the documentation
should warn about this explicitly.
---
 reference/datetime/datetimeinterface/format.xml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/reference/datetime/datetimeinterface/format.xml b/reference/datetime/datetimeinterface/format.xml
index c22d0c467f74..39a49ecbf57b 100644
--- a/reference/datetime/datetimeinterface/format.xml
+++ b/reference/datetime/datetimeinterface/format.xml
@@ -321,7 +321,7 @@
          </row>
          <row>
           <entry><literal>c</literal></entry>
-          <entry>ISO 8601 date</entry>
+          <entry>ISO 8601 date. Only compatible with the non-expanded format (up to year 9999). Later dates will result in an invalid string. For later dates and expanded format, see <literal>x</literal> and <literal>X</literal>.</entry>
           <entry>2004-02-12T15:19:21+00:00</entry>
          </row>
          <row>